Commutator and brush type switch



R. s. CURRY. JR 2,368,644

COHMUTATOR AND BRUSH TYPE SWITCH Filed Oct. 24, 1942 2 Sheets-Sheet 1 INVENTOR R. S. CURRY; JR.

ATTORNEY Feb.'6, 1945. 'R. s. CURRY, JR 2,353,644

COMMUTATOR AND BRUSH TYPE SWITCH File'gl .Oct. 24, 1942 2 Sheets-Sheet? FIG.8

FIGH

' 66 s5 67 as INVENTOR R. S. CURRY JR.

ATTORNEY Patented Feb. 5, 1945 2,368,644 COMMUTATOR AND BRUSH TYPE SWITCH Robert S. Curry, In, Baldwin, N.Y.,

Sperry Gyroscope Company, Inc.,

assignor to Brooklyn,

N. Y., a corporation of New York Application October 24. 1942, Serial No. 463,295,

1 Claim.

This invention relates to a commutator and brush type switch for controlling an electrically responsive device operable to correct tilt of the rotor bearing case of a gyro vertical instrument.

An object of the invention is to provide a controller of this character which operates as a reversing switch.

The primary feature of the invention resides in the provision of a switch in which the 360 degree efiective commutator portion thereof includes a gravitationally responsive member for positioning the same with respect to the gyro rotor bearing case of the instrument. v

Another feature ofthe invention is provided by the arrangement and connections of the respective segment parts of the commutator of the switch. v

Other objects, features and structural details of the invention will be apparent from the following description when read in relation to the accompanying drawings, wherein,

Fig. 1 is a plan view of a gyro vertical instrument of the artificial horizon type with the casing thereof shown in section.

Fig. 2 is a detail section view taken on line 2-2,

'in Fig. 1.

Fig. 3 is an enlarged detail section view taken on line 3-3, in Fig. 1.

Fig. 4 is an exploded view of a switch constructed in accordance with the present invention this instrument includes an outer casing I which.

i in the present instance is provided with a window be spun pneumatically or electrically as desired.

In the present instance,

showing the electrical connections of the respec tive segments thereof.

Fig. 5 is a view similar to Fig. 4 showing a modiQ fled form of the improved switch.

Fig. 6 is a detail side elevation of a gyro rotor bearing case with a gravity responsive tilt correcting means mounted thereon.

Fig. '7 is a plan view of therotor Fig. 6.

Fig. 8 is a detail circuit diagram showing the improved switch interposed between theenergy source and the type of tilt correcting device illustrated in Figs. 6 and 'l.

Fig. 9 is a view similar to Fig. 8 with the switch interposed between the energy source and the type of tilt correcting device illustrated in Fig. 1.

Fig. 10 is a perspective detail view of a further modified type of switch constructed in accordance with the invention, and

Fig. 11 is a development showing the arrangement of the commutator segments in the type of switch shown in Fig. 10.

Fig. 1, theinstrument in inventive concepts are emillustration is a conven- With reference which the present bodied for purposes of case shown in II in its front wall. Within the casing ID of the instrument, a gimbal ring I2 is mounted to-pivot about a horizontal axis which may be situated parallel to the fore and aft ax s of the craft in which the instrument is employed. This axis is defined by the trunnions l3 and i4 and the respective bearings l5 and It. The gyro rotor bearing case of the instrument is indicated at II. This case is mounted in a conventional manner by means of the extending trunnions l8 and I9 and the respective bearings 20 and 2| located in the gimbal ring l2. The athwartship axis of the case ll provided by the oppositely disposed bearings 20 and 2| is normally horizontal and is situated in mutually perpendicular relation with respect to the pivot axis of the ring. The gyro rotor hearing case is consequently universally mounted with respect to the outer casing l0. A conventional gyro rotor (not shown) is contained within the rotor bearing case and is mounted therein to spin about a normally vertical axis by means of suitable bearings (not shown). The yro rotor may a suitable motor may be employed in this connection, the stator windings 22 of the motor being shown in Figs. 8 and 9. The windings 22 of the motor are energized from a suitable source of three-phase alternating current electrical energy as indicated at 23.

In each 0! the forms of the invention shown one of the leads by which energy is supplied to spin the rotor is utilized in connection with a further leading to supply electrical energy to an electrically responsive device operable tocorrect tilt of the rotor bearing case from a normal position in. its universal mounting inwhich the spin axis of the gyro rotor is vertical. In Fig; 1, the tilt correcting means is provided by an electromagnetic couple consisting of annular coils 24 and 25 and the permanent magnets 26 which are mounted on the exterior of the rotor bearing case I1. Coils 24 and 25 are selectively energized from the suitable direct current source indicated at 21, Figs. 8 and 9, by way of the switching controllerof the present invention to produce amagnetic field which combines with the magnetic field of the magnets. to obtain a torque about the desired axis of the case to restore the same to a normal erected position, as well understood in the art. v

In the form of tilt correcting device shown in Figs. 6 and '7, oppositely disposed solenoids 28-29 and Iii-3| are mounted on the top of the rotor bearing case l1. Pairs of the solenoids are connected in series relation and when energized from the direct current source through means of the improved switch controller effect the shifting of a movable normally centralized weight member 32 to a position on the case in which it exerts a torque that restores the case to a normally erected position. No novelty is claimed for either of the forms of electrically responsive tilt correcting devices shown in the present application.

The controlling means constructed in accordance with the teaching of the present invention for a tilt correcting device of the electrically responsive type, as hereinbefore described, operates as a reversing switch in which form the same are diagrammatically indicated at 34 and 35 in Figs. 8 and 9. The switches are located at the respective axes of universal mounting of the case l1 and are respectively interposed in the circuit by which energy is led to either the coils 24 or 25, or the pairs of solenoids 28-23 or 3ll-3I. Suitable slip rings of conventional construction, as shown in Figs. 8 and 9, are employed at the respective axes of the universal mounting of the case i1 to provide for the passage of electrical energy at these points between the source of supply and the tilt correcting device as shown in either of the circuit figures. In operation, the normally inefl'ective switches selectively close the circuit from source to coil or solenoid so that a particular one thereof is energized in the proper sense that the necessary corrective torque is exerted by the electrically responsive tilt correcting device to restore the case I1 to its normal or erected position.

With reference to Figs. 2 to 4, inclusive, one of the improved switches is shown in detail. To avoid repetition, the switch employed about the athwartship axis of the instrument which is similar in construction is not described. Switch 34, as shown, is of the commutator and brush type. The commutator 36 of the switch illustrated in Figs. 2, 3 and 4 is formed of two coaxial rings 40 and 4|, one of which is constructed to include three current conducting segments 42, 43, 44. The commutator is mounted in this instance on trunnion l4 by means of bearing 45, the conducting segments being concentric with the axis of the ring I2. The plurality of spaced conducting segments employed in this form of the invention is six in number, the segments for ring 4! being indicated at 42', 43' and 44'. A weight 46 is mountedon the body of the commutator 36 which is located eccentric to the axis of the same and provides a gravitationally responsive member for positioning the same. The angular dimensions 01' the spaced segments 42-42 and 43-43 are approximately ninety degrees and the segments 44 and 44 are approximately one hundred and eighty degrees. Further, the switch includes two fixedly mounted brushes 41 and 48 on the ring I2 which are positioned to selectively engage the respective adjacent segment pairs 42-43 and 42'-43'. Brushes 41 and 48, in this ,instance, supply energy to, for example, coil 24. Two other brushes 49 and 50 are fixedly mounted on the arm 11 and respectively contactsegments 44 and 44'. Energy from the source 21 is supplied to the switch by way brushes 4! and 50. The switch segments are electrically connected to control the operation of the tilt correcting device in accordance with tilt of the case l1, and in the instance shown, segments 44 and 44' are respectively connected to segments 42 and 42. The remaining connected segments are 44 with 43, and

42 with 43. In switch 35, two of the four brushes are mounted in the ring l2 and the other two on the rotor bearing case IT. The brushes lightly engage th segments of the switch and tend to damp the pendulous commutator. The described type of switch is effective within a range of operation in which the spin axis of the gyro rotor .strument having a greater range of relative dis placement of the rotor bearing case, such as ocours in the attitude gyro instrument shown and described in the copending application of Orland E. Esval, Walter Wrigley 'and Robert Haskins, J r., Serial No. 445,760, filed June 4, 1942. In this type of gyro-vertical no limiting stops are employed and no cage, so that during acrobatics the gyro remains free but may go into the gimbal lock position, in which case the gimbal ring may be caused to turn through 180 degrees although the gyroscope itself remains upright. The form of contactor shown in Fig. 5, however, overcomes this difficulty and will operate equally well throughout 360 degrees. With reference to this figure, the gravity positioned commutator is shown as formed of four coaxial rings 5|, 52, 53 and 54. stance contact the 360 degree extending conducting segments 55 and 56 of the two outside rings 5| and 54. Theinwardly disposed rings 52 and 53 each include four substantially degree extending spaced segments as respectively indicated at 51, 58, 59, 60 and 51', 56, 59, 60. The take-off brushes 4! and 48 selectively contact adjacent pairs of the segments 51-58 or 59-50 and 5'l-5B' or 59-60' depending on the posi-' tion of the gyro case with relation to a vertical reference at a particular instant, the switch being continuously effective to properly energize the tilt correcting means, such as shown in Fig. 1 in this instance, from the source to control the case l1. The segment connections for this type of control switch are shown to include cross leads between segments 51-59, 58-60, 51'-59 and 58-60' as well as connections between segments 55, 51, 60' and segments 56, 59 and 58'.

A further modification of the invention is shown in Figs. 10 and 11, in which the commutator is formed of three connected segments as indicated at 65, 66 and 61. As shown in the development of the commutator, segments 65 and 61 are oppositely disposed and displaced axially. Segment 56 is a common connecting segment and is continuously engaged by lead in brush 58. Brushes 69 and 10 are positioned to selectively contact the respective axially spaced segments 65 and 61. With this type of switch a center tap connection is made to coil 24, thus obviating the employment of one of the previously utilized four brushes.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying'drawings shall be interpreted as illustrative and not in a limiting sense.

Lead in brushes 49 and 50 in this in-- What is claimed is: I The combination with a universally mounted vertical gyroscope, of electrical means, for correcting the tilt thereoi'. comprising a commutator-type switch positioned atone axis thereof in,-

cluding two commutators each having four symasses 3 bearing on each commutator, said brushes on the Que-hand and said commutators and slip rings on the other hand being mounted one on the gyroscope and the other pendulously, and a torque-applying winding mounted adjacent the other axis of said gyroscope and electrically connected between such brushes, whereby, upon relative inclination of the gyroscope, current .is caused to pass in one direction or the other 10 through said winding, dependent on the direction of tilt, and said commutator remains operative throughout 360 degrees of relative tilt. ROBERT S. CURRY, JR. 

